Set Up Post-Dial DTMF String for a Contact In this case, you can use commas to represent the gap in time where the conference recording is 'asking you to enter your PIN' with the numerical string you've entered automatically executing after the set duration. It's particularly valuable if you have standard conference bridges you repeatedly call into wherein you need to enter a PIN or ID number to access the bridge. Post-dial DTMF strings allow you to append PINs or other ID numbers to a particular contact number, using the comma (',') character to represent 2-second pauses in sequence. Although DTMF works in normal human voice range, the combination of inharmonic frequencies makes it hard for the human voice to impersonate.Īlthough mobile phone networks use digital signals instead of DTMF for direct dialing, DTMF is still used over mobile phones to navigate automated systems such as phone menus, voice menus and other advanced calling services.Dialpad Ai Voice, Ai Sales, and Ai Contact Center customers on the Pro and Enterprise plans are able to use post-dial DTMF strings.

The frequencies were chosen to avoid harmonics : no frequency is a multiple of another, the difference between any two frequencies does not equal any of the frequencies, and the sum of any two frequencies does not equal any of the frequencies. With DTMF, each keypress on your phone generates tones made of two specific frequencies. Over the years, DTMF has replaced Pulse dialing, the early type of telephone dialing in which short pulses were used to relay the dialed number. Dual-Tone Multi-Frequency (DTMF) is the signal that you generate when you press an ordinary telephone's touch keys.

Dtmf dialing